


On Plato's Theory of Soulmates

by SchrodingersHalfling



Category: Shadowhunters (TV), The Shadowhunter Chronicles - All Media Types
Genre: Alternate Universe - Human, Fluff, M/M, Making Out, Marriage Proposal, Mundane!AU, chaotic idiots, dumbass lovers
Language: English
Status: Completed
Published: 2021-02-28
Updated: 2021-02-28
Packaged: 2021-03-12 03:20:15
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,728
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29753265
Author URL: https://archiveofourown.org/users/SchrodingersHalfling/pseuds/SchrodingersHalfling
Summary: “You said once you thought you’d be married by the time you were thirty.”The truth is Magnus doesn’t actually remember saying that, but it does sound like something he might have said before Camille crushed his heart and smothered the naïve romantic in him. He does, however, know that what he has now with Alec is so much more than anything he could have ever dreamt up.
Relationships: Magnus Bane/Alec Lightwood
Comments: 10
Kudos: 103





	On Plato's Theory of Soulmates

A week before Magnus’ thirtieth birthday finds him pressing his best friend up against the wall less than a foot inside the front door of their flat, one ringed hand pinning Alec’s wrists above their heads as they kiss. Magnus has his other hand curled around Alec’s hip, the tips of his fingers dragging lazily against warm skin, only occasionally dipping below the waistband of Alec’s jeans just to come back up in teasing stokes.

Alec whines, low and breathy, as his fingers trail up again and Magnus grins, swallowing the sound as he continues to very thoroughly delve into Alec’s mouth.

Despite the fact that they’ve only been doing this for a couple months now there’s no denying how natural this feels, how perfectly they fit into each other. The way they click together, not just physically, makes Magnus think that perhaps Plato was on to something with his bizarre, yet oddly charming theory on soulmates.

Magnus has certainly always, undeniably, been his best self with Alexander.

Magnus’ own shirt hangs mostly loose where Alec has tugged it free from his pants, but that had been before Magnus had caught him, restraining them both from taking things further by distracting Alec with heated kisses.

That had been a good ten minutes ago and, unfortunately for the heat growing in his belly, Magnus has ulterior motives for so determinedly kissing Alec into a mindless haze.

Finally releasing Alec’s hands, Magnus sinks his now free hand into Alec’s already ruffled hair, keeping the taller man exactly where he wants him as he drags his lips over Alec’s mouth, across the five o’clock shadow he so dearly loves and down that delectable neck. Alec’s arms drape heavily over his shoulders as Magnus kisses, nips and sucks his way up to Alec’s ear and, with one final tug of Alec earlobe with his teeth, Magnus purrs, “Now would be an excellent time to tell me what’s been bothering you, dear heart.”

Magnus pulls away to watch the confusion flood into Alec’s eyes.

“Magnus what…I…what, no…don’t what…” he stumbles and stutters, eyelids fluttering.

It’s been subtle, but it has been there. And Magnus would be a poor best friend and lover to not have noticed the pensive, contemplative and occasionally hesitant funk Alec’s fallen into these past couple days.

The golden and green flecks in his eyes glow all that much brighter in the dark of their streetlamp lit apartment. Cheeks flushed, well past his way to sex-hair and with his lips kiss-swollen and tinted purple from Magnus’ lipstick, Alec has never looked more beautiful.

Sliding his hands out of Alec’s hair and from under his shirt, Magnus cups Alec’s face gently in his palms and leans back in to place a feather light kiss to Alec’s lips, his head tilting slightly as he softly says, “What’s going on, Alexander?”

Alec’s eyes fall shut as he breathes heavily, and when he opens them they are clear, if still lust blown and confused. “The fuck, Magnus!?”

Magnus tsks, only mildly annoyed that he couldn’t seduce the problems out of his lover.

“You’ve been off,” Magnus says, staring Alec in the eye. “Something is bothering you, it has been for days, and like the nice boyfriend I am I have given you time to work through it yourself or come to me, but neither have happened so now I’m asking.”

“And you couldn’t just, you know… _ask_?” Alec’s voice jumps up an octave or three with incredulity. He waves a wild hand up and down, gesturing at the way Magnus still has him crowded up against the wall, their rumpled clothes and the overall sexual tension that has risen up between them during their heated make out session, but also during the night in general. “You had to go and…and _seduce_ it out of me?” his voice is still rather high and despite how serious he is about getting whatever it is out of Alec, Magnus is finding he quite enjoys it.

“Well, no. I could have I suppose,” Magnus grins blithely. “But I thought this might be more fun for the both of us.”

Although Alec raises a very unimpressed eyebrow, Magnus can clearly see the amusement shining in his eyes.

“And that maybe you’d be in a better mood and tell me instead of being pissed,” Magnus mumbles, biting at his lip in nervousness, not above pleading with wide eyes. Hoping Alec would find him adorable and not manipulative, even though much of their night was deliberately planned with the underlying intention of lulling Alec into a more open frame of mind where he’d be less inclined to bottle everything up.

The nervousness though, that was the one thing that Magnus wasn’t putting on. This thing between them, for all that it feels right, it was still new. Barely a few months of being lovers after well over a decade of being best friends.

Alec makes a frustrated, growling sort of sound and tugs Magnus forward the few inches between them by his neck to plant a solid and affectionate, yet decidedly unheated kiss to Magnus’ lips.

“You’re lucky you’re cute, you asshole,” Alec declares with a fond sort of scowl.

His hands press at Magnus’ shoulders and Magnus lets himself be pushed back off Alec, wondering all the while what the hell is going on. Up until about thirty seconds ago he’d been so sure he’d had the upper hand on the situation, but Alec has somehow managed to flip everything on its head and now Magnus is utterly lost.

Alec’s hands slide down his arms until Magnus’ hands are being cradled by Alec’s.

“It’s your birthday in a week,” Alec says suddenly.

“It is.”

“You’re turning thirty.”

“I am.”

Magnus no longer cares that Alec is the only one with a clue as to what this conversation is about. He may have no idea what is going on, but at least they are finally getting somewhere.

“Come on, love. Use your words,” Magnus teases, bemused as Alec grows more mulish.

That too was almost unbelievable in how right it felt. Eleven weeks, that’s how long it has been since Alec had turned to him late one night and said, _I love you_. Eleven weeks since Magnus had smiled and said it right back before kissing him as if they’d been doing it their entire lives and not the very first time that it was.

The attraction had been there, how could it not have been; Alec was probably the most gorgeous person Magnus had ever met. But the love, that had crept up on him slowly. Magnus would have been uncomfortable with it, with the fact that they’d both been ignoring the attraction they felt for each other had things been different. But it wasn’t as if either of them had spent the better part of a decade hopelessly pinning. They’d both been in relationships of varying degrees of seriousness over the years. Their friendship had never once suffered because of their once secret crushes.

“You said once you thought you’d be married by the time you were thirty.”

The truth is Magnus doesn’t actually remember saying that, but it does sound like something he might have said before Camille crushed his heart and smothered the naïve romantic in him. He does, however, know that what he has now with Alec is so much more than anything he could have ever dreamt up.

“I thought maybe,” Alec continues, oblivious of where Magnus’ mind has strayed. “I didn’t think I could ever have this, could ever be this happy. And I don’t know what you want. If you even still want after _her_. I thought our friends would be there, laughing at us and telling us we’re idiots and that they all saw this coming since the moment we met. But I love you, I think a part of me always has. I like who I am with you, because you make me want to better me for my own self and not for someone else.”

Magnus’ mind damn near went blank as a thought occurred to him, what Alec was trying to say in his own adorable, convoluted way. Because Alec has always been the common sense in this partnership. Alec is the one who pulls Magnus back and thinks things through when Magnus is happily forging ahead without a second thought. Magnus is rash and whimsical; Alec is prudent and steadfast.

“And I know it’s too soon but it’s your birthday next week and–”

“Alexander, marry me,” Magnus blurts out, slapping a palm to his mouth when his brain finally catches up to the idiotic thing.

“I love you! It’s not too soon!” he rushes to say, all but flailing his arms around as Alec remains dead still. “Let’s get married.”

“A week!” Alec voice goes higher than before and Magnus genuinely hadn’t thought that possible. “A week, Magnus! I was terrified you’d call me insane and… and _fuck you_ , fuck. _I_ have a _ring_.”

Alec fumbles, hand shoved down a pocket before he’s thrusting the Lightwood family ring out to Magnus.

Magnus bypasses Alec’s hand and the ring, smacking his mouth right back onto Alec’s in a bruising kiss. “Yes. _Yes_. I’ll marry you, you marry me. Yes, to it all. Not about it being too soon, or about not wanting because of the vile bitch. But all the rest, goddamn yes,” Magnus babbles in between pressing kisses to every inch of Alec’s face.

“Yes? Yes!” Alec demands, creating, in Magnus’ opinion, a highly unnecessary space between them

They are both blinking back tears, grinning through sniffs as Alec pulls Magnus back in.

Magnus, who lets himself be pulled back in for a moment before tugging at Alec as he takes a step backwards, blindly guiding them across the room until they are tipping over onto the couch, kissing breathlessly and playfully. The kisses petering off until they’re just lying there tangled together.

At one point Alec grabs Magnus’ left hand and slowly removes every single ring that is on it before reverently sliding the Lightwood ring onto his finger.

“When?” Magnus asks.

Sprawled out over him Alec shrugs and gave a sheepish smile. “I applied for a marriage license four days ago. Whenever you want.”

Magnus snorts, grinning. “ _You_ are the _best thing_.”

**Author's Note:**

> i wrote this for exactly two reasons  
> 1\. i love a good hijacked proposal  
> 2\. i really just wanted to use the "fuck you, i have a ring' line
> 
> Also,  
> for those interested Plato's theory is essentially, and in the shortest version possible:  
> When humans were originally created, it was with four arms, four legs and a head with two faces. Zeus feared their power and split them in two (humans as we are now), condeming them to spend eternity searching for their other half.  
> At least, that's the mythological version i was thinking of when writing this.


End file.
